NPC movements

CLAUDE.md

@@ -423,6 +423,29 @@ above the declaration with no blank line in between.
 
 ---
 
+## Color system
+
+Colors are defined in `src/dusk/display/color.csv` and code-generated
+into a `color.h` header by `tools/color/csv/__main__.py`.
+
+Each row in the CSV has `name,r,g,b,a` with channel values in `[0.0, 1.0]`.
+The script emits four `#define` variants per color plus a bare alias:
+
+```
+COLOR_<NAME>_4B   color4b(r8, g8, b8, a8)   // default alias target
+COLOR_<NAME>_3B   color3b(r8, g8, b8)
+COLOR_<NAME>_3F   color3f(rf, gf, bf)
+COLOR_<NAME>_4F   color4f(rf, gf, bf, af)
+COLOR_<NAME>      COLOR_<NAME>_4B
+```
+
+`color_t` is `color4b_t` (four `uint8_t` channels).
+
+To add a new color, append a row to `color.csv` and rebuild — do not
+hand-edit the generated header.
+
+---
+
 ## Tests
 - Tests live in `test/` mirroring `src/dusk/` structure.
 - Use cmocka; include `dusktest.h`.